Fistulae after surgery are a typical postoperative (PO) complication. In the past, fistula detection was performed by X-Ray or CT. The aim of this study is to show that ultrasound using the novel "Pumping Probe Technique" (PPT) is an alternative method of detecting urinary-entero-urinary fistulae.  In order to represent the ureter exactly, we use the "Kung Fu Technique" (KFT). A simple and safe method for the detection of entero-urinary fistulae is the Poppy test, but an exact localization cannot be proven. By means of ultrasound in pumping probe technique a exact localization of the fistula is possible. A new intermural complete sealing ureteric stent prevents leakage, covers the tissue and allows the tissue to heal without further measures. After fistula detection a complete sealing ureteric stent was inserted in each patient.

In 84 cases between June 2012 to February 2019 we used the new PPT in both endoluminal sonography and elastography to visualize ureteric fistulae. The technique involves the forward and backward movement of an ultrasound probe to generate pressure in the fistula, thus leading to a movement of the fluid within so that it can be detected. We use the "Kung Fu Technique" (KFT) to represent the ureter accurately, simply and safely. The right ureter will be seen by a 45 degree turn to the outside of the endfire probe in its distal total length of 6 cm.  Same procedure of the left ureter with opposite rotation. The ureter to the arteria iliaca communis is visible transrectally in a length of 11cm.  After a detailed presentation of the ureter, the pumping probe test is performed to visualize the fistula. A fully covered ureteric stent (Allium URS) was positioned under radiology and cystoscopic or ureterorenocopic control. The stent placement is done with standard instruments like cystoscope or ureterorenoscope in seldinger technique using x-rays. The stent is removed by means of ureterorenoscopes and a grasping forceps. The fistula is immediately covered and closed by the stent. A urine flow through the fistula is prevented. This allows the fistula to heal completely.

A fistula was detected by elastography in only 49 of the cases, however using ultrasound 72 of 84 were visualized, both imaging modalities were performed with the new PPT in combination with KFT. The mean examination time was 15min (+- 7min).  X-Ray and CT were then used to confirm the diagnosis. We found 45 ureterico-vaginal fistulae, 16 ureteric-douglas fistulae, 12 ureteric-enteric fistulae and 11 arterio-ureteric fistula using this method. Each patient was then treated with the implantation of a self-expanding covered stent.  After 8-12 weeks the stent was removed. Ureterorenoscopically and radiologically the fistula occlusion could be detected. In 76 of the 84 cases the fistula was successfully closed. In no case were strictures found.

Endoluminal sonography and elastography using the novel PPT in combination with the KFT detected approximately 85.7% of the fistula cases. MRI or X-Ray are mostly not more required. By means of elastography, the fistula tract could also be detected in. In the retrograde x-Ray, the fistula tract could always be detected. The learning curve of a practiced physician for the visualisation of the ureters and the fistulae in KFT and PPT is low. You need 10 sonographies in the middle to use the procedures well. Due to the minimally invasive diagnosis and treatment, patient acceptance was very high.

Endoluminal sonography and elastography using the novel PPT in combination with the KTF detected approximately 85.7% of the fistula cases. The subsequent diagnostic and management of ureteric fistulae with stents can be performed gently, safely and quickly. The cure rate by using a sealing ureteric stent was high at 90,5%. Patient acceptance of the examination procedure is very high.